Re: OSPF Area0 Vs Non-Zero Area

Anyone who has time to clarify few OSPF doubts below:

Thanks & Regards,
Bilal Hansrod

Sent from my iPhone

On 03/11/2010, at 10:55 PM, Bilal Hansrod <bilal.hansrod_at_gmail.com>
wrote:

> Hello Group,
>
> Can anyone please clarify my doubts in relation to route selected
> for non-zero area. Here is the questions;
>
> Q1: R6 in area 1 connected to R1(ABR) that is in area zero via
> Virtual Link. R6 is also connected to R4 (ABR) that is the same area
> 1 and also area 0. A route from area 2 is learned via R1 and R4. If
> the metric of route is lower from R4, does it prefer R4 as a exit
> point. As this is learned via are 1 vs area 0 that is R1 route . I
> always thought it will prefer route via area 0 that it has learned
> via R1.
>
> Also capability transit is enabled on Cisco and if you disable this
> statement it will forcefully route via area 0 ABR (R1). Also, it is
> same affect if R6 has link into Area 0 (non VL) acting as ABR.
>
> Q2: To calculate overall cost to IA routes, why do we see cost to
> DR? If R6 wants to route to IP address in Area 2, I need to check
> the below:
>
> 1. Cost from ABR to destination IP
> 2. Cost from R6 to ABR and also we check DR cost, but if I
> have R6 as a DR, why do I need to add cost to myself i.e. R6.
>
> I am confused, or someone explain both scanrios.
>
> Regards,
>
> Bilal Hansrod

Blogs and organic groups at http://www.ccie.net
Received on Thu Nov 04 2010 - 12:35:11 ART